Concept cars present futurephiles with a profound dilemma: they often portray some of the more interesting near-term possible changes to automotive design, but inevitably, the commercially-available cars that eventually come out usually bear little resemblance to the concept. Concept cars represent the potential for revolution, but commercial cars rarely represent more than timid evolution. This painful dichotomy will undoubtedly be seen yet again in whatever results from Daimler-Chrysler's DCX "Bionic" concept car.

Daimler-Chrysler is one of the companies caught flat-footed by the rapid growth in consumer demand for hybrid cars. Much of their high-efficiency auto research has gone to fuel cell vehicle designs (years away at best) and to diesel cars for the European market. The four-passenger DCX is also a diesel, but exceeds the most restrictive EU emissions standards. It gets 70 miles per gallon (US method), better than the Prius or even the ultra-efficient (but tiny) Honda Insight -- and at a constant speed of 90 km/hr, it gets up to 84 mpg.

But what stands out about the DCX is the look. The shape is, in a word, funky -- but that's because it's designed to mimic the super-streamlined shape of the boxfish.

It has its home in the coral reefs, lagoons and seaweed of the tropical seas, where it has a great deal in common with cars in many respects. It needs to conserve its strength and move with the least possible consumption of energy, which requires powerful muscles and a streamlined shape. It must withstand high pressures and protect its body during collisions, which requires a rigid outer skin. And it needs to move in confined spaces in its search for food, which requires good manoeuvrability.

[...] Applied to automotive engineering, the boxfish is therefore an ideal example of rigidity and aerodynamics. Moreover, its rectangular anatomy is practically identical to the cross-section of a car body. And so the boxfish became the model for a so far unique automotive development project.

Daimler-Chrysler looked outside the standard auto designer fold for assistance with the DCX, bringing in biologists as well as engineers. As a result, the DCX has a drag coefficient of 0.19 -- closer to the boxfish ideal of 0.04 than the typical car's 0.35-0.4 -- which helps to explain its fuel efficiency. It's a bit startling, as the customary expectation of what a "streamlined" car looks like is more akin to the flattened wedge of an Insight. And if you think the current Prius design got odd looks when it first appeared, imagine the reaction to the DCX.

Alas, the double-takes and fervent debate will almost certainly remain in the realm of fantasy. The DCX is a test-bed for a variety of technologies (from improved diesel engines to auto body manufacturing techniques), but is unlikely to ever hit the road in its current shape. Automakers are just too timid, too afraid to step outside the fold of the expected. Rare exceptions do occur -- but the DCX won't be one of them.

It is beautiful, and its beautiful to see company's thinking seriously about biomickry. Hopefully with the competition in the automarket some company, like Daimler-Chrysler, will go for style and brake the stagnancy in body design.

The drag coefficient of 0.19 is amazing thanks to the streamlined boxfish shape. However, the boxfish has fins to help it manoeuvre, whereas the DCX probably suffers from lack of downforce to provide grip to the wheels.

The car will be able to accelerate to and maintain great speeds but I'm worried about when the car heads into a curvy highway off-ramp. The next step would need to be to make the car be able to easily modify its aerodynamic components so that it can increase its increase its drag coefficient when it needs to.

Posted by: Jack Sam on 8 Jun 05

That thing looks intensely practical - think of all the interior space! There are only two reasons I wouldn't go out and buy one tomorrow if DC put them on the lot:

I'm concerned about visibility to the rear and the safety implications.

I just bought a new car last year.

It's a pity that DC didn't keep going after making the ESX3 vehicle for the PNGV program; think of where they'd be today. If some US carmaker had a super-Prius class hybrid already on the market and hackers converting it to a GO-HEV, our current worries about disruptions of oil supplies would be greatly reduced.

Hmm.. Cool that they're using biomimicry, but it's not really getting them anything.

A drag coefficient of .19 is good, but not amazing-- the EV1 accomplished that over ten years ago. And the amount of aerodynamic drag is not just the coefficient, it's the coefficient TIMES frontal area, which this car definitely has more of, thus making it less aerodynamic than an Insight or an EV1.

Besides- isn't this biomimetics taken out of context? If it were a submarine or airship then great. But fish that swim at speed along the bottom of the sea, especially in shallow water, seem to adapt to 'flat fish' - rays and the like. More like the sports cars that ripple along hugging the ground. And with width you get the opportunity for downthrust to increase traction against the tarmac despite low weight at high speed. But it's not cool to say that convention has it right, I guess.

Posted by: Ian White on 9 Jun 05

Besides- isn't this biomimetics taken out of context? If it were a submarine or airship then great. But fish that swim at speed along the bottom of the sea, especially in shallow water, seem to adapt to 'flat fish' - rays and the like. More like the sports cars that ripple along hugging the ground. And with width you get the opportunity for downthrust to increase traction